What is Hepatopulmonary Syndrome?
The hepatopulmonary syndrome is a condition that involves both the liver and lungs. As a syndrome, this is characterized by a triad of symptoms. The disease is composed of the problem hypoxemia (decreased oxygen in the blood), intrapulmonary vascular dilatations and a liver problem. Those affected with hepatopulmonary syndrome are adults with liver problems and also does not spare children with an underlying portal hypertension disease. A chronic liver disease also places the child at risk for developing this syndrome.
Intrapulmonary Dilatation Seen as Hazy Lines in the Lungs
The prevalence rate of this syndrome is 5-29% in adults who have a hepatic disorder. The children on the other hand have a prevalence rate of 0.5-20% that is with an underlying hepatic condition. Those with acquired childhood cirrhosis have a prevalence of 2-4% for hepatopulmonary syndrome.
The condition is said to be in two forms:
The condition involves the right to left shunting of the lungs. This is known as the most common type of hepatopulmonary syndrome which basically involves dilatation of the capillaries during the exchange of oxygen. As a result, there is less oxygen containment in the alveoli- where gas exchange is the primary role, and the ventilation process is altered.
This accumulates about 10% of hepatopulmonary syndrome cases. The oxygen exchange is yet again not attained normally, as arteriovenous shunts in the circulatory system have not attained its purpose. The anatomic shunts place the ineffective oxygen exchange, making this type of the syndrome as very grave one.
Symptoms of hepatopulmonary syndrome
Those with hepatopulmonary syndrome are expected to present pulmonary symptoms as well as liver problem manifestations. The following present the characteristics of the disease:
- Hypoxemia is a prominent presentation. This is most recognizable especially when a person is suffering from liver cirrhosis.
- Cyanosis is noted among patients. This is described as the bluish or purple discoloration of our skin. The inside membranes or tissues of our body is also affected of the discoloration and is primary caused by a deficient flow of oxygenated blood.
- Digital clubbing (a known manifestation of hypoxemia and is described as the fingers’ tips are enlarged) is observed. This is due to the lack of oxygenation.
- Plethora of spider nevi is noted. This is identified as spider angioma where there are small angiomata on the skin. This is the spider-like appearance of the vessels visible on the skin. This is basically a manifestation of a hepatic problem.
- Platypnea is noted or simply known as dyspnea upon standing.
- Orthodeoxia is a manifestation. This is the sudden fall of the partial oxygen of the patient while in standing position.
- Increased Nitric oxide levels. This is noted due to its vasodilator component.
- Esophageal varices might develop. These are dilated veins found in the esophagus.
- Increased heart rate is noted as a sign of compensation from hypoxemia.
Clubbing and Cyanosis of the Fingers
Causes & Risk factors
The hepatopulmonary syndrome is said to be caused by three distinct sources:
- Presence of an arteriovenous shunt. This shunt is basically a product from a surgical intervention that provides a vessel indicated to provide a pathway for blood exchange between an artery and vein. This is highly indicated for patients for hemodiaysis.
- Impaired function of the alveolocapillary in maintaining the diffusion-perfusion process. The pulmonary vessels are quite affected when a vasodilator takes place and acts in desaturating the oxygen. Making the erythrocytes incapable of providing adequate oxygenated blood.
- Ventilation and perfusion process is uneven. When there is an underlying lung condition, it is expected that one will suffer from perfusion problems. In cases of liver cirrhosis, there shall be adecrease in perfusion in specific lung areas as ventilation is poor.
- Others. Portal hypertension is considered a significant cause of hepatopulmonary syndrome. The chronic use of substances for vasodilatation can induce the syndrome.
The physical examination of the patient can assist us in the process of diagnosing hepatopulmonary syndrome. When the triad manifestations of the syndrome have been noted, then prompting of the following tests is performed:
- Chest X-ray. This test shall present interstitial markings. These marking are bilateral in opacity and may be accompanied by nodules.
- Echocardiograph. This test shall identify presence of intrapulmonary shunts. This is a screening test for HPS.
- The levels of partial oxygen are tested. The level of PaO2 less than 70 mm Hg indicates hypoxemia. Checking the client’s level of PaO2 when he or she is in an upright position is essential for HPS when it has a decrease of more than 3 mm Hg. This shall indicate for orthodeoxia, a clear manifestation of the syndrome.
The definitive treatment of hepatopulmonary syndrome is not yet found. Instead, supportive and palliative treatment is provided to clients with HPS.
- Supplement the client with oxygen. We should not let the patient assume a standing position abruptly.
- Nitrous oxide inhibitor is provided. Even though there has been less support with this treatment, it has been found to reverse vasodilatation.
- Control the client’s hypertension. Providing the suitable treatment for the client is a great help in managing the disease.
- Orthotopic liver transplantation. This is considered as a treatment of choice when no other interventions seem to work. This is simply known as liver transplant
In general, the condition is considered to have a poor prognosis. The hepatopulmonary syndrome is basically from an underlying chronic disease and is a result of ineffective treatment and management of a liver disease. When liver transplantation has not been performed, the result shall be unfavorable on the part of the client. As a person has been diagnosed of the syndrome, it is vital that prompt check-ups are to be done and proper disease observation is done for 2 to 3 years.
The syndrome is quite hard to manage once the affected are provided with a limited life expectancy after diagnosis. Studies show that there is about 24 months to 5 years of survival rate among the reported cases of HPS. When surgical intervention such as liver transplant has not been performed, the survival rate shall be lower than expected.